Australia Weather News

Climate scientists have cautioned against "crying wolf" on the unfolding impacts of climate change, as new research suggests a dramatic upswing in heatwaves across northern Australia.

Released by think tank The Australia Institute this week, the Kimberley HeatWatch report pointed to an unprecedented rise in hot weather across the West Australia's Kimberley by the end of the century.

The paper, commissioned by local conservation group Environs Kimberley, suggested that without adequate policies to reduce global temperatures, the number of "extreme heat days" where temperatures reach 35 degrees Celsius and over would increase dramatically each year.

"Extreme heat days in Broome are projected to increase from an average of 81 days above 35 degrees, to up to 195 days by 2050 and potentially up to 286 days by 2090," the report said.

Under the same scenario, the paper stated that Derby and Kununurra would be hit with up to 328 extreme heat days a year by 2090, Halls Creek 284, and Bidyadanga — WA's largest remote community — 327 days.

That situation — defined by the paper as the "business as usual" situation of high-polluting governments failing to reduce carbon emissions — would also lead to substantial increases in days over 40C and nights over 25C, the report found.

Coupled with the region's humid, tropical climate, the report argued the temperature jump posed significant risks to residents' health and welfare.

Economic prospects would also take a hit, the report stated, with the Kimberley's key tourism, agriculture and construction industries all likely to be impacted by the estimated temperature increase.

It said emissions-reduction policies designed to limit global temperature increases to the globally accepted target of 1.5C were the key way to stabilise and limit the temperature increases.

Report's forecasting questioned

The report's catastrophic forecasts have been difficult to independently verify.

Curtin University climate scientist and Intergovernmental Panel on Climate Change contributor, Peter Newman, said this was particularly clear at the more extreme end.

"I don't know they could claim there is a real basis for what they're saying," Professor Newman said.

"Other than that it is getting hotter; but that much hotter? I'm not so sure."

Professor Newman said the dire forecasts ran the risk of emboldening opponents of climate action if they were not eventually met.

"If you overstate and you're crying wolf all the time, people stop listening to you."

The Australia Institute's Peter Ogge defended the research and said outlining the seriousness of the situation was critical.

"I'm confident that the increase in days over 35C will definitely be of that order of magnitude," he said.

"We've highlighted how bad it could get, but we've included the full range of projections in there.

"I think it's just really important we tell people the truth about what's going on — I don't think watering it down really helps anyone in the long run."

Data backs temperature increases: CSIRO

CSIRO regional climate research team leader, John Clarke, whose data underpinned many of the report's conclusions, said plotting and predicting climate models was always a challenging prospect.

"The value for Broome for days over 35C are, I would say, higher than they should be, but the values for the other locations and Broome days over 40C seem reasonable to me," he said

"I think the 60 days [over 40C for Broome] is probably plausible.

"The general story that extreme heat is getting worse is absolutely uncontentious."

He said modelling indicated a broad range of potential temperature outcomes; with the report focusing on the highest projected results.

"They have emphasised the upper limits and that's because of the message they want to convey," Mr Clarke said.

"It would have been good if they'd also spoken about the minimums, but even the minimums are a pretty nasty increase in temperature."

Focus needed on opportunity, as well as risk

The report identified gas in the Canning Basin — the subject of intense debate within the Kimberley over hydraulic fracturing — as a potential source of emissions the Government should look to limit.

Professor Newman said the report failed to factor in ongoing economic shifts, particularly growing demand for renewable energy.

"I just don't think it's going to happen; the sheer economics of it is going to undermine what they're saying," he said.

"We're going to be leaving most of those gas resources in the ground."

Professor Newman said greater support needed to be put in place for industries and communities leading the charge on renewable energy.

"It doesn't mean we get scared and blame someone," he said.

"We have to get on, do what we can personally and get our industries to start seeing they have to be part of the solution — not part of the problem."